Benedict V was elected pope (May, 964) in very critical circumstances. The powerful emperor, Otho I, had forcibly deposed the unworthy John XII, and had replaced him by a nominee of his own who took the title of Leo VIII. But at the first opportunity the Romans expelled Leo, and on the death (14 May, 964) of the lawful pope, John XII, elected the Cardinal-Deacon Benedict (known from his learning as Grammaticus-see Benedict of Soracte, xxxvii). Otho was furious, marched on Rome, seized Benedict, and put an end to his pontificate (23 June, 964. -Liutprand, Hist. Ottonis, xxi; Thietmar, Chron., II, 18). It is more probable that Benedict was degraded by force than that he voluntarily declared himself an intruder. After reinstating Leo, Otho left Rome and carried Benedict with him to Germany. Placed under the care of Adaldag, Archbishop of Hamburg-Bremen, who treated him with great consideration, he was even then acknowledged as pope by some of the German clergy. His remains, first laid to rest in the cathedral at Hamburg, were afterwards translated to Rome (Adam of Bremen, Gesta, II, 10; IV, 39, 40; VI, 53).

The most important source for the history of the first nine popes who bore the name of Benedict is the biographies in the Liber Pontificalis, of which the most useful edition is that of Duchesne, Le Liber Pontificalis (Paris, 1886-92), and the latest that of Mommsen, Gesta Pontif. Roman. (to the end of the reign of Constantine only, Berlin, 1898). Jaffé, Regesta Pont. Rom. (2d ed., Leipzig, 1885), gives a summary of the letters of each pope and tells where they may be read at length. Modern accounts of these popes will be found in any large Church history, or history of the City of Rome. The fullest account in English of most of them is to be read in Mann, Lives of the Popes in the Early Middle Ages (London, 1902, passim).